Is Fortnite Sharable?

My girlfriend and I want to get Fortnite, but since the download for the program is free, I was wondering if you download the key or does buying grant the account access, like The Elder Scrolls Online does? If that is the case, I'll just wait for the physical version, since one of our accounts wouldn't be able to play it.

Asked people on the PSN and they confirmed only the main account has access to the game. So if you have to have multiple people, even on the same system, you need the physical version.